The big three of Oracle, IBM and Microsoft continue to dominate the relational database sector but market researchers are being forced to change the way they study the market by the rise of open-source and hosted products.

Revenue from global relational databases was $15.2bn in 2006, up 14.2 percent year on year, Gartner said. The 85.6 percent lion’s share of that went to the leaders, all of which grew income. Microsoft made the most notable leap, up 28 percent.

In a statement, Gartner research director Colleen Graham, said database customers “show no sign of flagging in their pursuit of performance management and overarching enterprise information management initiatives”.

Oracle continues to lead the market with a 47.1 percent market share while IBM took 21.1 percent and Microsoft 17.4 percent.

More interestingly, the platforms on which databases are being deployed are on the move. While Unix (34.8 percent) and Windows (34.5 percent) continue to vie for supremacy, Linux grew 67 percent to account for 15.5 percent of the sector.

That growth will be good news for Oracle -- which has extended its dominance on Unix to build a substantial Linux business -- but also for open-source alternatives such as MySQL and EnterpriseDB.

Gartner said that its software research group is changing the way it analyses the market in recognition of the move to open-source and hosted models. The firm said it is moving from a pure licence revenue review to a broader model incorporating updates, subscriptions, hosting and maintenance.